I’m not sure what did is on my gardenia
I thought it was mould but I don’t think it is
I’ve tried different sprays but nothing has helped
Any ideas please
Many thanks


Thanks for contacting Toronto Master Gardeners.  If you want a definitive diagnosis for this problem you might consider bringing a leaf from your plant to the store where you bought it. Having said that, your photograph suggests that there is armored scale on your gardenia.  Scale insects suck the sap from garden and indoor plants.  Well-tended healthy plants are able to tolerate light populations of these insects and so they do not necessarily require control.  Severe infestations may result in poor growth.

The control the infestation:

  • Isolate the gardenia from other house plants.
  • Remove any heavily infested leaves and place them in the garbage.
  • For less infested leaves dab a cotton tipped applicator dipped in rubbing alcohol on the dark spots.
  • Manually scrape off scales that still remain.
  • Wash the leaves in lukewarm water to remove any remaining rubbing alcohol.
  • With the advice from a reputable nursery, purchase an insecticidal soap that can be tolerated by a gardenia plant and use as directed.

Plants that are healthy are less vulnerable to scale. Gardenias are notoriously finicky.  For cultural practices that promote healthy gardenias click here

Good luck with your gardenia.